Can't get Mesh to unwrap properly
without an blend file i have to guess, but it seems to me, that you missed some uv marks on one end of each of the objects. A cubic object needs to have 3 UV Marks on each of its ends. I made a picture to explain it futher:  If that does not solve the problem, please upload the blend file.
For getting the top and bottom face separated from the object, mark the howl face: